/Engine/Source/Runtime/AudioMixer/Public/Quartz/AudioMixerClockHandle.h
Returns the current progress until the next occurrence of the provided musical duration as a float value from 0 (previous beat) to 1 (next beat). This is useful for indexing into curves to animate parameters to musical time. Ms and Phase offsets are combined internally.
float GetBeatProgressPercent ( EQuartzCommandQuantization QuantizationBoundary, float PhaseOffset, float MsOffset )